diff --git a/backend/api/jest.config.ts b/backend/api/jest.config.ts
index 7f9a4c35..d88064a3 100644
--- a/backend/api/jest.config.ts
+++ b/backend/api/jest.config.ts
@@ -26,4 +26,8 @@ module.exports = {
 
   collectCoverageFrom: ['src/**/*.{ts,tsx}', '!src/**/*.d.ts'],
   silent: true,
+  // Each ts-jest worker is a full TS-compiling process; the default (cpus - 1) can spawn enough
+  // of them in parallel to exhaust memory on high-core-count machines.
+  maxWorkers: '50%',
+  workerIdleMemoryLimit: '512MB',
 }
diff --git a/backend/email/jest.config.ts b/backend/email/jest.config.ts
index 45675fa9..014598a8 100644
--- a/backend/email/jest.config.ts
+++ b/backend/email/jest.config.ts
@@ -23,4 +23,8 @@ module.exports = {
 
   collectCoverageFrom: ['src/**/*.{ts,tsx}', '!src/**/*.d.ts'],
   silent: true,
+  // Each ts-jest worker is a full TS-compiling process; the default (cpus - 1) can spawn enough
+  // of them in parallel to exhaust memory on high-core-count machines.
+  maxWorkers: '50%',
+  workerIdleMemoryLimit: '512MB',
 }
diff --git a/backend/shared/jest.config.ts b/backend/shared/jest.config.ts
index efb9b955..d6cf0fa9 100644
--- a/backend/shared/jest.config.ts
+++ b/backend/shared/jest.config.ts
@@ -27,4 +27,8 @@ module.exports = {
 
   collectCoverageFrom: ['src/**/*.{ts,tsx}', '!src/**/*.d.ts'],
   silent: true,
+  // Each ts-jest worker is a full TS-compiling process; the default (cpus - 1) can spawn enough
+  // of them in parallel to exhaust memory on high-core-count machines.
+  maxWorkers: '50%',
+  workerIdleMemoryLimit: '512MB',
 }
diff --git a/common/jest.config.ts b/common/jest.config.ts
index 57028c6e..0ccd8ab7 100644
--- a/common/jest.config.ts
+++ b/common/jest.config.ts
@@ -12,4 +12,8 @@ module.exports = {
   testMatch: ['**/*.test.ts'],
   collectCoverageFrom: ['src/**/*.{ts,tsx}', '!src/**/*.d.ts'],
   silent: true,
+  // Each ts-jest worker is a full TS-compiling process; the default (cpus - 1) can spawn enough
+  // of them in parallel to exhaust memory on high-core-count machines.
+  maxWorkers: '50%',
+  workerIdleMemoryLimit: '512MB',
 }
diff --git a/jest.config.ts b/jest.config.ts
index b2fa03e0..311f3bba 100644
--- a/jest.config.ts
+++ b/jest.config.ts
@@ -21,4 +21,8 @@ module.exports = {
     '<rootDir>/web',
   ],
   silent: true,
+  // Each ts-jest worker is a full TS-compiling process; the default (cpus - 1) can spawn enough
+  // of them in parallel to exhaust memory on high-core-count machines.
+  maxWorkers: '50%',
+  workerIdleMemoryLimit: '512MB',
 }
diff --git a/web/jest.config.js b/web/jest.config.js
index 45675fa9..014598a8 100644
--- a/web/jest.config.js
+++ b/web/jest.config.js
@@ -23,4 +23,8 @@ module.exports = {
 
   collectCoverageFrom: ['src/**/*.{ts,tsx}', '!src/**/*.d.ts'],
   silent: true,
+  // Each ts-jest worker is a full TS-compiling process; the default (cpus - 1) can spawn enough
+  // of them in parallel to exhaust memory on high-core-count machines.
+  maxWorkers: '50%',
+  workerIdleMemoryLimit: '512MB',
 }