diff --git a/README.md b/README.md
index c9b4488..2de6619 100644
--- a/README.md
+++ b/README.md
@@ -2,19 +2,52 @@
 
 [![npm version](https://badge.fury.io/js/fastest-jest-runner.svg)](https://www.npmjs.com/package/fastest-jest-runner)
 
-Setup:
+###Motivation
+From what I discovered, there are two major reasons of jest slowness, compared to jasmine e.g. 
+1) for every test file jest is creating new env, importing all the modules, creating jsdom env etc
+2) memory leaks, which have even more effect becauase of 1) reason.
+
+With jest aproach:
+- memory leaks could not be fixed conceptually (using vm.Context), because memory could be leaked through core modules and globals (e.g. console).
+- first could not be speed up either, modules should be executed for every testfile, otherwise they will affect each other.
+
+This runner:
+- fixes memory leaks by design: every test is run in new, forked, process, which memory being copied from main process. Process then will end and exit, not affecting and share runtime with parent process.
+- while modules execution problem is not "fixed", it could be improved a lot by creating custom "snapshots", which has imported modules and created objects which then will be used by all tests. Amount of "warmed up" memory does not affect fork time.
+
+#####Tested only with jest 29
+
+###How it works:
+This runner is utilizing posix fork syscall.
+Fork() is relatively cheap (~1ms), it clones (copy on write) all memory pages, file descriptors and current thread callstack of process.
+Because nodejs does not support fork(), C++ extension is written and node is run in single thread mode (with some caveats with worker thread pool).
+
+Every test is run in new process, created by fork() call.
+Communication is set up by unix sockets.
+Fork is called from one of "snapshot" processes, which has warmed up env: required/imported modules, jsdom, whatever user save in global.
+If `snapshotBuilderPath` is not set, default snapshot builder is applied: by default it's only init jest test env (jsdom), test runner (jasmine or circus)
+
+If you want best results - you will need to write custom snapshot builder.
+Basically you can import all common modules, used by majority of tests.
+You can even import all modules, it will only increase time of snapshot creation, not every test time.
+But imported modules could not be mocked.
+Last could be get arounded by marking tests with custom pragma and use empty snapshot for it (see advanced usage)
+
+###Scheme:
+
+![alt text](docs/design.png "Design")
+
+###Setup:
 1) `yarn add fastest-jest-runner`
 2) write in `jest.config`: `"runner": "fastest-jest-runner"`
 
-Advanced usage:
+###Advanced usage:
 [using custom snapshots](tests/e2e/snapshots/package.json)
 
-Public
-
-Tested only with jest 29
-
-Not working:
+###Not working:
 - custom jest runners, except jasmine2 and circus (can be impl)
 - watch mode (can be impl)
-- windows
-- snapshots (can be impl)
+- Windows OS
+- jest snapshots (can be impl)
+- mocking modules after require in custom snapshots
+- worker threads, created in custom snapshot
diff --git a/docs/design.excalidraw b/docs/design.excalidraw
new file mode 100644
index 0000000..c70f98d
--- /dev/null
+++ b/docs/design.excalidraw
@@ -0,0 +1,1213 @@
+{
+  "type": "excalidraw",
+  "version": 2,
+  "source": "https://excalidraw.com",
+  "elements": [
+    {
+      "id": "UTrRnPtJj5ntI5vJdRAtD",
+      "type": "rectangle",
+      "x": 474.43677031473953,
+      "y": 156.45051040867702,
+      "width": 155.70339965820312,
+      "height": 101.80416870117188,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 2109353500,
+      "version": 198,
+      "versionNonce": 1986577956,
+      "isDeleted": false,
+      "boundElements": [
+        {
+          "type": "text",
+          "id": "lsBhuu0hYNR291dsZ_nIf"
+        },
+        {
+          "id": "l17VWMgvuYW0UFQJQorxr",
+          "type": "arrow"
+        }
+      ],
+      "updated": 1665312636202,
+      "link": null,
+      "locked": false
+    },
+    {
+      "id": "lsBhuu0hYNR291dsZ_nIf",
+      "type": "text",
+      "x": 504.2884701438411,
+      "y": 195.35259475926296,
+      "width": 96,
+      "height": 24,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 1852868252,
+      "version": 101,
+      "versionNonce": 369696284,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312636202,
+      "link": null,
+      "locked": false,
+      "text": "jest-cli",
+      "fontSize": 20,
+      "fontFamily": 3,
+      "textAlign": "center",
+      "verticalAlign": "middle",
+      "baseline": 20,
+      "containerId": "UTrRnPtJj5ntI5vJdRAtD",
+      "originalText": "jest-cli"
+    },
+    {
+      "id": "sKcrnF78-NDYK5pmlNj8L",
+      "type": "rectangle",
+      "x": 408.34028846858064,
+      "y": 337.6092283558917,
+      "width": 297,
+      "height": 154,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 1395525156,
+      "version": 417,
+      "versionNonce": 975410972,
+      "isDeleted": false,
+      "boundElements": [
+        {
+          "type": "text",
+          "id": "iyTG-vQpAoOrHctyYgzsS"
+        },
+        {
+          "id": "l17VWMgvuYW0UFQJQorxr",
+          "type": "arrow"
+        },
+        {
+          "id": "lOi3fxfRMAwMOAJoIGBRS",
+          "type": "arrow"
+        },
+        {
+          "id": "dfhxIZpfxAdYPvDpLuqY1",
+          "type": "arrow"
+        }
+      ],
+      "updated": 1665312591069,
+      "link": null,
+      "locked": false
+    },
+    {
+      "id": "iyTG-vQpAoOrHctyYgzsS",
+      "type": "text",
+      "x": 415.84028846858064,
+      "y": 366.6092283558917,
+      "width": 282,
+      "height": 96,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 1128600100,
+      "version": 466,
+      "versionNonce": 484047012,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312591069,
+      "link": null,
+      "locked": false,
+      "text": "main worker process\n(loading jest env: \nresolver, transformers, \njsdom)",
+      "fontSize": 20,
+      "fontFamily": 3,
+      "textAlign": "center",
+      "verticalAlign": "middle",
+      "baseline": 92,
+      "containerId": "sKcrnF78-NDYK5pmlNj8L",
+      "originalText": "main worker process\n(loading jest env: resolver, transformers, jsdom)"
+    },
+    {
+      "id": "l17VWMgvuYW0UFQJQorxr",
+      "type": "arrow",
+      "x": 552.4276716975033,
+      "y": 259.476389314927,
+      "width": 0.9188161565211885,
+      "height": 65.72979338666778,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "round",
+      "seed": 1738604060,
+      "version": 800,
+      "versionNonce": 603388572,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312636202,
+      "link": null,
+      "locked": false,
+      "points": [
+        [
+          0,
+          0
+        ],
+        [
+          -0.9188161565211885,
+          65.72979338666778
+        ]
+      ],
+      "lastCommittedPoint": null,
+      "startBinding": {
+        "elementId": "UTrRnPtJj5ntI5vJdRAtD",
+        "gap": 1.221710205078125,
+        "focus": -0.011894923666685528
+      },
+      "endBinding": {
+        "elementId": "sKcrnF78-NDYK5pmlNj8L",
+        "gap": 12.403045654296875,
+        "focus": -0.04399873148601383
+      },
+      "startArrowhead": null,
+      "endArrowhead": "arrow"
+    },
+    {
+      "id": "lOi3fxfRMAwMOAJoIGBRS",
+      "type": "arrow",
+      "x": 469.32344719464174,
+      "y": 493.6202756357393,
+      "width": 36.868254901719524,
+      "height": 75.66484200743548,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "round",
+      "seed": 31004828,
+      "version": 1011,
+      "versionNonce": 1269243812,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312591069,
+      "link": null,
+      "locked": false,
+      "points": [
+        [
+          0,
+          0
+        ],
+        [
+          -36.868254901719524,
+          75.66484200743548
+        ]
+      ],
+      "lastCommittedPoint": null,
+      "startBinding": {
+        "elementId": "sKcrnF78-NDYK5pmlNj8L",
+        "gap": 2.0110472798476016,
+        "focus": 0.26333084843999754
+      },
+      "endBinding": {
+        "elementId": "vdNYs06ubBJ-ZyN-1EXrp",
+        "gap": 5.5580973963368585,
+        "focus": -0.19498990974672972
+      },
+      "startArrowhead": null,
+      "endArrowhead": "arrow"
+    },
+    {
+      "id": "vdNYs06ubBJ-ZyN-1EXrp",
+      "type": "rectangle",
+      "x": 331.3974914618959,
+      "y": 574.8432150395116,
+      "width": 181,
+      "height": 130,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 767958692,
+      "version": 394,
+      "versionNonce": 1033920412,
+      "isDeleted": false,
+      "boundElements": [
+        {
+          "type": "text",
+          "id": "9FZ1r4JI6KdX69B1vhkaP"
+        },
+        {
+          "id": "lOi3fxfRMAwMOAJoIGBRS",
+          "type": "arrow"
+        },
+        {
+          "id": "4dSXPa67vwEmssNGCpQMk",
+          "type": "arrow"
+        },
+        {
+          "id": "rI_tA4mIrxW3JQmiWRoJW",
+          "type": "arrow"
+        }
+      ],
+      "updated": 1665311969799,
+      "link": null,
+      "locked": false
+    },
+    {
+      "id": "9FZ1r4JI6KdX69B1vhkaP",
+      "type": "text",
+      "x": 345.3974914618959,
+      "y": 579.8432150395116,
+      "width": 153,
+      "height": 120,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 18694172,
+      "version": 362,
+      "versionNonce": 1464594212,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665311943938,
+      "link": null,
+      "locked": false,
+      "text": "snapshot \n\"units\"\n\nrunning user \nsetup",
+      "fontSize": 20,
+      "fontFamily": 3,
+      "textAlign": "center",
+      "verticalAlign": "middle",
+      "baseline": 116,
+      "containerId": "vdNYs06ubBJ-ZyN-1EXrp",
+      "originalText": "snapshot \"units\"\n\nrunning user setup"
+    },
+    {
+      "type": "rectangle",
+      "version": 466,
+      "versionNonce": 946538916,
+      "isDeleted": false,
+      "id": "kBMQONoKupNFHQpBrE9vO",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 574.0617027972194,
+      "y": 573.3971877061836,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 181,
+      "height": 130,
+      "seed": 222547236,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [
+        {
+          "id": "RExGqYd0OATPQgx1LMZbW",
+          "type": "text"
+        },
+        {
+          "id": "lOi3fxfRMAwMOAJoIGBRS",
+          "type": "arrow"
+        },
+        {
+          "type": "text",
+          "id": "RExGqYd0OATPQgx1LMZbW"
+        },
+        {
+          "id": "dfhxIZpfxAdYPvDpLuqY1",
+          "type": "arrow"
+        },
+        {
+          "id": "8t15eWS7KEuE16Ww9ZJzS",
+          "type": "arrow"
+        }
+      ],
+      "updated": 1665311989425,
+      "link": null,
+      "locked": false
+    },
+    {
+      "type": "text",
+      "version": 439,
+      "versionNonce": 188695588,
+      "isDeleted": false,
+      "id": "RExGqYd0OATPQgx1LMZbW",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 588.0617027972194,
+      "y": 578.3971877061836,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 153,
+      "height": 120,
+      "seed": 864421660,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665311949262,
+      "link": null,
+      "locked": false,
+      "fontSize": 20,
+      "fontFamily": 3,
+      "text": "snapshot \n\"specs\"\n\nrunning user \nsetup",
+      "baseline": 116,
+      "textAlign": "center",
+      "verticalAlign": "middle",
+      "containerId": "kBMQONoKupNFHQpBrE9vO",
+      "originalText": "snapshot \"specs\"\n\nrunning user setup"
+    },
+    {
+      "id": "dfhxIZpfxAdYPvDpLuqY1",
+      "type": "arrow",
+      "x": 584.5987581520305,
+      "y": 492.7307919631913,
+      "width": 31.149027613298472,
+      "height": 75.27112139157208,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "round",
+      "seed": 919297828,
+      "version": 255,
+      "versionNonce": 2107055260,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312591069,
+      "link": null,
+      "locked": false,
+      "points": [
+        [
+          0,
+          0
+        ],
+        [
+          13.899663338773735,
+          39.21792120884021
+        ],
+        [
+          31.149027613298472,
+          75.27112139157208
+        ]
+      ],
+      "lastCommittedPoint": null,
+      "startBinding": {
+        "elementId": "sKcrnF78-NDYK5pmlNj8L",
+        "gap": 1.1215636072996062,
+        "focus": -0.0004012168506082013
+      },
+      "endBinding": {
+        "elementId": "kBMQONoKupNFHQpBrE9vO",
+        "focus": -0.18017979208526666,
+        "gap": 5.395274351420198
+      },
+      "startArrowhead": null,
+      "endArrowhead": "arrow"
+    },
+    {
+      "id": "nkbNpwZ__UcAQ5-ZNHJRX",
+      "type": "text",
+      "x": 596.4764506267759,
+      "y": 508.9302563611094,
+      "width": 143,
+      "height": 24,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 1063463836,
+      "version": 121,
+      "versionNonce": 825251620,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665311793404,
+      "link": null,
+      "locked": false,
+      "text": "posix fork()",
+      "fontSize": 20,
+      "fontFamily": 3,
+      "textAlign": "left",
+      "verticalAlign": "top",
+      "baseline": 20,
+      "containerId": null,
+      "originalText": "posix fork()"
+    },
+    {
+      "type": "text",
+      "version": 198,
+      "versionNonce": 1669466660,
+      "isDeleted": false,
+      "id": "AQd9pX9ccmxQp1n01_xCV",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 315.42789006323204,
+      "y": 516.0437835915913,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 143,
+      "height": 24,
+      "seed": 643894300,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665311788121,
+      "link": null,
+      "locked": false,
+      "fontSize": 20,
+      "fontFamily": 3,
+      "text": "posix fork()",
+      "baseline": 20,
+      "textAlign": "left",
+      "verticalAlign": "top",
+      "containerId": null,
+      "originalText": "posix fork()"
+    },
+    {
+      "id": "ZHsf00HfpO017bfIHWXOP",
+      "type": "rectangle",
+      "x": 90.8525930306987,
+      "y": 277.6770732608642,
+      "width": 1304.2318008017523,
+      "height": 692.7034063764495,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "dotted",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 998299804,
+      "version": 443,
+      "versionNonce": 1195606180,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312639020,
+      "link": null,
+      "locked": false
+    },
+    {
+      "id": "fkNxnc7nPoAtdwx27qmYg",
+      "type": "text",
+      "x": 117.29184786663842,
+      "y": 299.1712551379527,
+      "width": 225,
+      "height": 24,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "dotted",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 792688540,
+      "version": 114,
+      "versionNonce": 94394396,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312597437,
+      "link": null,
+      "locked": false,
+      "text": "fastest-jest-runner",
+      "fontSize": 20,
+      "fontFamily": 3,
+      "textAlign": "left",
+      "verticalAlign": "top",
+      "baseline": 20,
+      "containerId": null,
+      "originalText": "fastest-jest-runner"
+    },
+    {
+      "id": "6CsmsU4iRvSvr5aoJOys0",
+      "type": "rectangle",
+      "x": 179.5044945436366,
+      "y": 788.3930040688145,
+      "width": 176,
+      "height": 119.19243955207742,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 1532970012,
+      "version": 172,
+      "versionNonce": 833995940,
+      "isDeleted": false,
+      "boundElements": [
+        {
+          "type": "text",
+          "id": "-marmILm0rQykfMMb32-F"
+        },
+        {
+          "id": "4dSXPa67vwEmssNGCpQMk",
+          "type": "arrow"
+        }
+      ],
+      "updated": 1665312021422,
+      "link": null,
+      "locked": false
+    },
+    {
+      "id": "-marmILm0rQykfMMb32-F",
+      "type": "text",
+      "x": 189.8896134444712,
+      "y": 811.9892238448533,
+      "width": 154,
+      "height": 48,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 1749268004,
+      "version": 117,
+      "versionNonce": 1089554332,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312021422,
+      "link": null,
+      "locked": false,
+      "text": "process for \ntest1.unit.ts",
+      "fontSize": 20,
+      "fontFamily": 3,
+      "textAlign": "center",
+      "verticalAlign": "middle",
+      "baseline": 44,
+      "containerId": "6CsmsU4iRvSvr5aoJOys0",
+      "originalText": "process for test1.unit.ts"
+    },
+    {
+      "type": "rectangle",
+      "version": 245,
+      "versionNonce": 1934189468,
+      "isDeleted": false,
+      "id": "2bETyPS4kMkVsfZMYgVVS",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 413.3627486522703,
+      "y": 798.9012879733735,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 176,
+      "height": 119.19243955207742,
+      "seed": 303488420,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [
+        {
+          "id": "MQFqjuAFghGxAS0rmZ7ql",
+          "type": "text"
+        },
+        {
+          "type": "text",
+          "id": "MQFqjuAFghGxAS0rmZ7ql"
+        },
+        {
+          "id": "rI_tA4mIrxW3JQmiWRoJW",
+          "type": "arrow"
+        }
+      ],
+      "updated": 1665311999039,
+      "link": null,
+      "locked": false
+    },
+    {
+      "type": "text",
+      "version": 193,
+      "versionNonce": 1260729380,
+      "isDeleted": false,
+      "id": "MQFqjuAFghGxAS0rmZ7ql",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 423.7478675531049,
+      "y": 822.4975077494123,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 154,
+      "height": 48,
+      "seed": 1703558812,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665311999039,
+      "link": null,
+      "locked": false,
+      "fontSize": 20,
+      "fontFamily": 3,
+      "text": "process for \ntest2.unit.ts",
+      "baseline": 44,
+      "textAlign": "center",
+      "verticalAlign": "middle",
+      "containerId": "2bETyPS4kMkVsfZMYgVVS",
+      "originalText": "process for test2.unit.ts"
+    },
+    {
+      "id": "4dSXPa67vwEmssNGCpQMk",
+      "type": "arrow",
+      "x": 372.9628317270799,
+      "y": 705.8432150395116,
+      "width": 85.94770784334503,
+      "height": 73.1652332248284,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "round",
+      "seed": 512700068,
+      "version": 99,
+      "versionNonce": 1662907420,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312021422,
+      "link": null,
+      "locked": false,
+      "points": [
+        [
+          0,
+          0
+        ],
+        [
+          -85.94770784334503,
+          73.1652332248284
+        ]
+      ],
+      "lastCommittedPoint": null,
+      "startBinding": {
+        "elementId": "vdNYs06ubBJ-ZyN-1EXrp",
+        "focus": -0.17101911122922672,
+        "gap": 1
+      },
+      "endBinding": {
+        "elementId": "6CsmsU4iRvSvr5aoJOys0",
+        "focus": -0.38935706193952696,
+        "gap": 9.384555804474587
+      },
+      "startArrowhead": null,
+      "endArrowhead": "arrow"
+    },
+    {
+      "id": "rI_tA4mIrxW3JQmiWRoJW",
+      "type": "arrow",
+      "x": 456.0821486127362,
+      "y": 709.3395399110843,
+      "width": 20.399286724366277,
+      "height": 83.85803611383278,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "round",
+      "seed": 17239708,
+      "version": 97,
+      "versionNonce": 540217252,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665311999039,
+      "link": null,
+      "locked": false,
+      "points": [
+        [
+          0,
+          0
+        ],
+        [
+          20.399286724366277,
+          83.85803611383278
+        ]
+      ],
+      "lastCommittedPoint": null,
+      "startBinding": {
+        "elementId": "vdNYs06ubBJ-ZyN-1EXrp",
+        "focus": -0.1610932748366243,
+        "gap": 4.49632487157271
+      },
+      "endBinding": {
+        "elementId": "2bETyPS4kMkVsfZMYgVVS",
+        "focus": -0.08777266635103567,
+        "gap": 5.703711948456487
+      },
+      "startArrowhead": null,
+      "endArrowhead": "arrow"
+    },
+    {
+      "type": "rectangle",
+      "version": 268,
+      "versionNonce": 1842937636,
+      "isDeleted": false,
+      "id": "QgM9AZhb3lLu9L8qXFXtU",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 690.4494109678097,
+      "y": 788.6253757728972,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 176,
+      "height": 119.19243955207742,
+      "seed": 1438596900,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [
+        {
+          "id": "IkfElmKhbLd9m8G_-Kp-B",
+          "type": "text"
+        },
+        {
+          "id": "IkfElmKhbLd9m8G_-Kp-B",
+          "type": "text"
+        },
+        {
+          "id": "rI_tA4mIrxW3JQmiWRoJW",
+          "type": "arrow"
+        },
+        {
+          "type": "text",
+          "id": "IkfElmKhbLd9m8G_-Kp-B"
+        },
+        {
+          "id": "8t15eWS7KEuE16Ww9ZJzS",
+          "type": "arrow"
+        }
+      ],
+      "updated": 1665311996338,
+      "link": null,
+      "locked": false
+    },
+    {
+      "type": "text",
+      "version": 224,
+      "versionNonce": 932508956,
+      "isDeleted": false,
+      "id": "IkfElmKhbLd9m8G_-Kp-B",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 700.8345298686444,
+      "y": 812.2215955489359,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 154,
+      "height": 48,
+      "seed": 1479718172,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665311996338,
+      "link": null,
+      "locked": false,
+      "fontSize": 20,
+      "fontFamily": 3,
+      "text": "process for \ntest1.spec.ts",
+      "baseline": 44,
+      "textAlign": "center",
+      "verticalAlign": "middle",
+      "containerId": "QgM9AZhb3lLu9L8qXFXtU",
+      "originalText": "process for test1.spec.ts"
+    },
+    {
+      "id": "8t15eWS7KEuE16Ww9ZJzS",
+      "type": "arrow",
+      "x": 687.4083084292727,
+      "y": 711.1209465761422,
+      "width": 60.77316398138851,
+      "height": 72.80815259175665,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "round",
+      "seed": 619224476,
+      "version": 120,
+      "versionNonce": 1945104796,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665311996338,
+      "link": null,
+      "locked": false,
+      "points": [
+        [
+          0,
+          0
+        ],
+        [
+          60.77316398138851,
+          72.80815259175665
+        ]
+      ],
+      "lastCommittedPoint": null,
+      "startBinding": {
+        "elementId": "kBMQONoKupNFHQpBrE9vO",
+        "focus": 0.26211211732641143,
+        "gap": 7.723758869958601
+      },
+      "endBinding": {
+        "elementId": "QgM9AZhb3lLu9L8qXFXtU",
+        "focus": 0.16985852294924403,
+        "gap": 4.696276604998445
+      },
+      "startArrowhead": null,
+      "endArrowhead": "arrow"
+    },
+    {
+      "type": "text",
+      "version": 151,
+      "versionNonce": 455246364,
+      "isDeleted": false,
+      "id": "V2R2vuD-sYvnBSBC-3qYW",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 655.7351120215915,
+      "y": 732.9435650272587,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 143,
+      "height": 24,
+      "seed": 1198144548,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665311997722,
+      "link": null,
+      "locked": false,
+      "fontSize": 20,
+      "fontFamily": 3,
+      "text": "posix fork()",
+      "baseline": 20,
+      "textAlign": "left",
+      "verticalAlign": "top",
+      "containerId": null,
+      "originalText": "posix fork()"
+    },
+    {
+      "type": "text",
+      "version": 229,
+      "versionNonce": 519262876,
+      "isDeleted": false,
+      "id": "yi_PvcHbGw_vwQEryj5mu",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 198.29569781081722,
+      "y": 713.667899370904,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 143,
+      "height": 24,
+      "seed": 678838308,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665312015022,
+      "link": null,
+      "locked": false,
+      "fontSize": 20,
+      "fontFamily": 3,
+      "text": "posix fork()",
+      "baseline": 20,
+      "textAlign": "left",
+      "verticalAlign": "top",
+      "containerId": null,
+      "originalText": "posix fork()"
+    },
+    {
+      "type": "text",
+      "version": 142,
+      "versionNonce": 1410239516,
+      "isDeleted": false,
+      "id": "Ijc1HMSe_7wxxILRJ2h3P",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 403.95657702602114,
+      "y": 733.0290639435171,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 143,
+      "height": 24,
+      "seed": 342766236,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665312004487,
+      "link": null,
+      "locked": false,
+      "fontSize": 20,
+      "fontFamily": 3,
+      "text": "posix fork()",
+      "baseline": 20,
+      "textAlign": "left",
+      "verticalAlign": "top",
+      "containerId": null,
+      "originalText": "posix fork()"
+    },
+    {
+      "id": "YJCMhq8BP3KHp39Sjz26O",
+      "type": "rectangle",
+      "x": 893.0493501476615,
+      "y": 791.0142750204225,
+      "width": 52.20773527972756,
+      "height": 123.41761441328117,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "dotted",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 1677791388,
+      "version": 132,
+      "versionNonce": 761082532,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312035838,
+      "link": null,
+      "locked": false
+    },
+    {
+      "type": "rectangle",
+      "version": 457,
+      "versionNonce": 383653796,
+      "isDeleted": false,
+      "id": "yvUKj87fD6FXl8IvWJbZ_",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "dotted",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 601.8108495899621,
+      "y": 792.2319888951254,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 52.20773527972756,
+      "height": 123.41761441328117,
+      "seed": 466495004,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665312050054,
+      "link": null,
+      "locked": false
+    },
+    {
+      "type": "rectangle",
+      "version": 261,
+      "versionNonce": 368989988,
+      "isDeleted": false,
+      "id": "ggHBa_drImZjMu8n--XOt",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "dotted",
+      "roughness": 1,
+      "opacity": 100,
+      "angle": 0,
+      "x": 962.2523146000935,
+      "y": 788.9873161123396,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "width": 52.20773527972756,
+      "height": 123.41761441328117,
+      "seed": 473003812,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "boundElements": [],
+      "updated": 1665312053720,
+      "link": null,
+      "locked": false
+    },
+    {
+      "id": "q3R-qA8Fta2jFMEkE-07q",
+      "type": "text",
+      "x": 740.7590335415525,
+      "y": 445.8977507993692,
+      "width": 528,
+      "height": 120,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "dotted",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 1060197796,
+      "version": 353,
+      "versionNonce": 128401308,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312594819,
+      "link": null,
+      "locked": false,
+      "text": "for each snapshotBuilder.snapshots:\n    process = fork(main worker process)\n    in process context:\n        run user warmup code(require('mod1'))\n    processPool[snapshotName] = process",
+      "fontSize": 20,
+      "fontFamily": 3,
+      "textAlign": "left",
+      "verticalAlign": "top",
+      "baseline": 116,
+      "containerId": null,
+      "originalText": "for each snapshotBuilder.snapshots:\n    process = fork(main worker process)\n    in process context:\n        run user warmup code(require('mod1'))\n    processPool[snapshotName] = process"
+    },
+    {
+      "id": "lI6-L6z_BLrdf0sskHlXq",
+      "type": "text",
+      "x": 800.6429211036718,
+      "y": 661.0949908785154,
+      "width": 564,
+      "height": 120,
+      "angle": 0,
+      "strokeColor": "#000000",
+      "backgroundColor": "transparent",
+      "fillStyle": "hachure",
+      "strokeWidth": 1,
+      "strokeStyle": "dotted",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "strokeSharpness": "sharp",
+      "seed": 474038300,
+      "version": 305,
+      "versionNonce": 624410652,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1665312797651,
+      "link": null,
+      "locked": false,
+      "text": "for each test:\n    snapshotName = snapshotBuilder.getSnapshot()\n    process = processPool[snapshotName]\n    fork(process)\n",
+      "fontSize": 20,
+      "fontFamily": 3,
+      "textAlign": "left",
+      "verticalAlign": "top",
+      "baseline": 116,
+      "containerId": null,
+      "originalText": "for each test:\n    snapshotName = snapshotBuilder.getSnapshot()\n    process = processPool[snapshotName]\n    fork(process)\n"
+    }
+  ],
+  "appState": {
+    "gridSize": null,
+    "viewBackgroundColor": "#ffffff"
+  },
+  "files": {}
+}
\ No newline at end of file
diff --git a/docs/design.png b/docs/design.png
new file mode 100644
index 0000000..b1907ad
Binary files /dev/null and b/docs/design.png differ
diff --git a/yarn.lock b/yarn.lock
index 511e911..f85ee5e 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4522,7 +4522,7 @@ __metadata:
 
 "typescript@patch:typescript@^4.8.2#~builtin<compat/typescript>":
   version: 4.8.2
-  resolution: "typescript@patch:typescript@npm%3A4.8.2#~builtin<compat/typescript>::version=4.8.2&hash=701156"
+  resolution: "typescript@patch:typescript@npm%3A4.8.2#~builtin<compat/typescript>::version=4.8.2&hash=a1c5e5"
   bin:
     tsc: bin/tsc
     tsserver: bin/tsserver