Certification

Senior TypeScript Developer

This certification is designed for experienced TypeScript developers who build real applications and make implementation decisions that affect correctness, maintainability, and delivery quality over time.

It validates senior-level capability in TypeScript type system design, API contracts, safe data modeling, application architecture, async workflow handling, frontend or full-stack code organization, testing strategy, and production-focused maintainability. The emphasis is on using TypeScript as an engineering tool for clarity and correctness, not simply as JavaScript with annotations.

Candidates are expected to demonstrate that they can design expressive and reliable types, reduce ambiguity in application behavior, model boundaries between modules and services, and keep large codebases understandable as they evolve. This includes making sound decisions around generics, narrowing, shared contracts, reusable abstractions, and the balance between strictness, developer experience, and delivery speed.

The certification is suitable for developers who already use TypeScript professionally and want to validate that they can build robust, scalable, and well-structured applications with senior-level technical discipline.

Get Certified

What this certification proves

Clear scope for candidates. Clear meaning for reviewers.

Passing result

What a pass confirms

This certificate confirms that the candidate demonstrated senior-level TypeScript development competence in building type-safe application architectures, designing reliable code contracts, and delivering production-ready software with strong engineering discipline.

Scope

What the exam validates

Scope includes TypeScript type system usage, generics and narrowing, contract design, module boundaries, async workflows, maintainable application structure, testing strategy, debugging, performance awareness, and long-term codebase maintainability decisions.

For reviewers

What someone can verify later

The public certificate page shows the holder name, score, issue date, certificate ID, and current verification status without relying on screenshots.

Share flow

Share one record, not a bundle of files

Use the certificate page as the primary proof. PDF stays available as a convenient copy, but the live page is the canonical record.

Official certificate page

What the verifier will see

Candidate name
Score and pass outcome
Date and certificate ID
Current verification status

Preparation topics

Topics covered by the exam question set.

Use this topic map as a preparation checklist. Questions in this certification are built from these concrete topic areas.

Core Types

primitive types
type aliases
interfaces
classes
tuples
optional properties
readonly arrays
index signatures
optional chaining
nullish coalescing

Narrowing and Safety

typeof narrowing
instanceof narrowing
in narrowing
type predicates
assertion functions
unknown
never type
catch variables
safe parsing
untrusted JSON
non-null guards
exhaustiveness checks

Utility Types

Partial
Required
Readonly
Pick
Omit
Record
Exclude
Extract
NonNullable
Parameters
ReturnType
Awaited
OmitThisParameter

Generics and Inference

generic functions
generic constraints
keyof
indexed access
generic defaults
const generics
NoInfer
overloads
wrapper typing
inference preservation
callback variance
explicit this

Conditional and Mapped Types

conditional types
distributive conditionals
non-distribution
infer
mapped types
key remapping
mapped modifiers
DeepReadonly
function stripping
tuple mapping

Unions and Literals

discriminated unions
correlated unions
literal unions
as const
satisfies
template literals
route params
event names
handler maps
branded types
opaque strings
unique symbols

Async and Iteration

promises
Promise.all
thenables
async states
iterators
generators
yield star
AsyncIterable
AsyncGenerator
for await
stream typing

Modules and Tooling

import type
export type
dynamic import
top-level await
ESM
CommonJS
strictNullChecks
noImplicitAny
noUncheckedIndexedAccess
exactOptionalPropertyTypes
strictPropertyInitialization
useUnknownInCatchVariables
moduleResolution
Node16
NodeNext
bundler
isolatedModules
verbatimModuleSyntax
project references
composite
declarationMap
conditional exports

Declarations and UI Typing

declaration files
ambient modules
module augmentation
global augmentation
declaration merging
namespaces
triple-slash references
Window augmentation
getElementById
querySelector
DOM events
InputEvent
listener this
TSX props
function components
intrinsic elements
generic TSX
JSX namespace
children typing

Advanced Runtime Features

enums
const enums
reverse mapping
symbols
symbol keys
bigint
decorators
metadata emit
using
await using
DisposableStack
AsyncDisposable
disposal order
SuppressedError

How the certification works

From voucher purchase to public certificate.

Once the candidate decides to pursue this certification, the path is simple: buy a voucher, exchange it for this certification, complete the exam, and receive the official certificate after a successful result.

Step 01

Buy a voucher for account balance

The candidate tops up voucher balance first. DevCerts does not sell this certification as a direct one-off checkout item.

Step 02

Choose this certification and exchange the voucher

When the candidate is ready, one voucher is consumed and DevCerts opens exam access for this certification.

Step 03

Pass and receive the official certificate page

After a successful valid result is received from Askium, DevCerts issues the certificate, publishes the public verification page, and keeps PDF available as a secondary copy.

Current certificate policy

What this certification page promises today

A certificate is issued only after a successful valid result.
The public verification page is the canonical certificate artifact.
The issued certificate is active and non-expiring in the current MVP.