Level path

Software Engineer

Mid SE

Own features and services with solid implementation judgment across neighboring layers.

Total concepts162

Curated for this specific career level.

Specific to this level40

Concepts explicitly listed in this level.

Knowledge tracks6

Concepts span multiple tracks and layers.

Job description signalsTypical responsibilities

Build and maintain production software using sound programming, design, testing, and debugging practices.
Collaborate with product, design, QA, operations, and other engineers to ship reliable features.
Participate in reviews, planning, incident follow-up, and continuous improvement of the codebase.
Own features end to end from design through implementation, testing, release, and support.
Make local technical tradeoffs and explain them clearly to teammates.
Improve reliability, maintainability, and observability of the systems you touch.
Collaborate with product, design, QA, operations, and adjacent engineering teams.

Cumulative view includes

Dev / Junior DevSE / Junior SEDev / Dev

Specific to this level 40Cumulative 162

Track / layer masteryConcept coverage by layer

{}

Software

35 concepts

Computer Networks9 System Design8 Software Design6 Security4 Databases3 Software Architecture2 Distributed Systems2 Programming1

Product

3 concepts

API Products3

OPS

Operations

2 concepts

Observability2

{}

Software

121 concepts

Software Design32 Programming23 Programming Languages13 Algorithms & Data Structures12 Databases10 Computer Networks9 System Design9 Security4 Software Architecture3 Quality Assurance3 Distributed Systems2 Operating Systems1

MGT

Management

16 concepts

Business Foundations10 Requirements & Planning4 Delivery Methodologies1 Team Leadership1

OPS

Operations

12 concepts

Build & Packaging5 Observability4 Local Development1 Continuous Integration1 Deployment1

Product

8 concepts

Developer Tools4 API Products3 Web Applications1

Theory

3 concepts

Algorithmic Analysis3

DATA

Data

2 concepts

Data Foundations2

Learning scopeConcepts by learning area

Specific to this level

Concepts introduced by this level

Level concepts

Programming Foundations

Learn the basic building blocks used to express behavior in code.

ConcurrencySoftware · Programmingworkingnew

Level concepts

Software Design

Structure code so it remains readable, testable, and maintainable as it grows.

SOLIDSoftware · Software Designworkingnew Dependency InjectionSoftware · Software Designworkingnew DRYSoftware · Software Designnew KISSSoftware · Software Designnew DTOSoftware · Software Designnew

Level concepts

Data & Persistence

Understand how applications store, retrieve, and protect durable state.

B-TreeSoftware · Databasesworkingnew Database NormalizationSoftware · Databasesworkingnew NoSQLSoftware · Databasesnew

Level concepts

Architecture & Systems

Design systems that handle growth, latency, failure, and multiple communicating components.

Level concepts

Production Awareness

Know how software is built, deployed, observed, and recovered in production.

MonitoringOperations · Observabilityworkingnew Input ValidationSoftware · Securityworkingnew RetrySoftware · System Designnew Circuit BreakerSoftware · System Designnew Rate LimitingSoftware · System Designnew TracingOperations · Observabilitynew

Cumulative level expectation

All concepts expected at this level

Inherited path

Coding Foundations

Developers begin by learning to translate requirements into working, readable code.

Inherited path

Developer Tooling

Daily development depends on version control, language tooling, static checks, and repeatable local workflows.

GitProduct · Developer Toolsawareness CompilerSoftware · Programming Languagesawareness InterpreterSoftware · Programming Languages Package ManagerOperations · Build & Packaging LintingOperations · Build & Packaging Code EditorProduct · Developer Tools CLISoftware · Operating Systems Version ControlProduct · Developer Tools DependencyOperations · Build & Packaging ArtifactOperations · Build & Packaging Development EnvironmentOperations · Local Development Software EcosystemSoftware · Programming

Inherited path

Testing & Debugging

A developer owns not only writing code, but proving that it behaves as intended.

Unit TestSoftware · quality-assuranceawareness DebuggerProduct · Developer Toolsawareness Error HandlingSoftware · Programming Code DocumentationSoftware · Software Design

Inherited path

Employment Basics

Technical candidates benefit from understanding who employs them, how they are paid, and which terms govern the working relationship.

EmployeeManagement · business-foundationsawareness ContractorManagement · business-foundationsawareness EORManagement · business-foundations Offer LetterManagement · business-foundations Employment ContractManagement · business-foundations CompensationManagement · business-foundations Employee BenefitsManagement · business-foundations Equity CompensationManagement · business-foundations PayrollManagement · business-foundations Statement of WorkManagement · business-foundations

Inherited path

Programming Foundations

Learn the basic building blocks used to express behavior in code.

Graph Data StructureSoftware · Algorithms & Data Structuresawareness Big O NotationTheory · Algorithmic Analysisawareness Requirements EngineeringManagement · Requirements & Planning Time ComplexityTheory · Algorithmic Analysis Space ComplexityTheory · Algorithmic Analysis TreeSoftware · Algorithms & Data Structures HeapSoftware · Algorithms & Data Structures Breadth-First SearchSoftware · Algorithms & Data Structures Depth-First SearchSoftware · Algorithms & Data Structures ConcurrencySoftware · Programmingworkingnew

Inherited path

Software Design

Structure code so it remains readable, testable, and maintainable as it grows.

Inherited path

Data & Persistence

Understand how applications store, retrieve, and protect durable state.

Relational DatabaseSoftware · Databasesawareness SQLSoftware · Databasesawareness Database IndexSoftware · Databases TransactionSoftware · Databases ACIDSoftware · Databases QueryData · Data Foundations Data ModelData · Data Foundations B-TreeSoftware · Databasesworkingnew Database NormalizationSoftware · Databasesworkingnew NoSQLSoftware · Databasesnew

Inherited path

Architecture & Systems

Design systems that handle growth, latency, failure, and multiple communicating components.

Inherited path

Production Awareness

Know how software is built, deployed, observed, and recovered in production.

CI/CD PipelineOperations · Continuous Integrationawareness Integration TestSoftware · quality-assuranceawareness System ObservabilityOperations · Observability MonitoringOperations · Observabilityworkingnew Input ValidationSoftware · Securityworkingnew RetrySoftware · System Designnew Circuit BreakerSoftware · System Designnew Rate LimitingSoftware · System Designnew TracingOperations · Observabilitynew

Inherited path

Application Design

Mid-level developers own complete features and make local design choices inside an established architecture.

AbstractionSoftware · Software Design EncapsulationSoftware · Software Design InheritanceSoftware · Software Design PolymorphismSoftware · Software Design ClosureSoftware · Programming ImmutabilitySoftware · Programming Side EffectSoftware · Programming Higher-Order FunctionSoftware · Programming Generic ProgrammingSoftware · Programming Inversion of ControlSoftware · Software Design YAGNISoftware · Software Design Code ComplexitySoftware · Software Design Cyclomatic ComplexitySoftware · Software Design Cognitive ComplexitySoftware · Software Design

Inherited path

Runtime & Data

Feature ownership requires practical knowledge of runtimes, memory management, and relational persistence.

RuntimeSoftware · Programming Languagesworking Garbage CollectionSoftware · Programming Languagesworking Call StackSoftware · Programming Heap MemorySoftware · Programming Event LoopSoftware · Programming SerializationSoftware · Programming JoinSoftware · Databases Write-Ahead LogSoftware · Databases Abstract Syntax TreeSoftware · Programming Languages LexerSoftware · Programming Languages ParserSoftware · Programming Languages BytecodeSoftware · Programming Languages

Inherited path

Delivery & Collaboration

Professional development includes the complete implementation loop, not only editing source files.

Code ReviewManagement · Team Leadershipworking Contract TestingSoftware · quality-assuranceworking Software DeploymentOperations · Deployment LoggingOperations · Observability MockSoftware · Software Design Semantic VersioningOperations · Build & Packaging PRDManagement · Requirements & Planning TSDSoftware · Software Design Product BacklogManagement · Requirements & Planning Backlog RefinementManagement · Requirements & Planning SprintManagement · Delivery Methodologies