Mathematical Systems Engineer

Shikhkarim
Mammadov

I design and build systems that handle financial transactions, high-throughput data flows, and complex distributed state — grounded in mathematical precision and long-term engineering discipline.

10K+Large-scale exam and SSR ecosystems
Concurrent requestsreal production traffic handled
5+
Years buildingproduction systems
4+EduArena, GitSense, Callman, Fintech systems
Major platformsarchitected end-to-end
30+Financial + product ecosystems
Microservicesenterprise ecosystem exposure
02./Systems

Selected work

Projects built with a focus on reliability, architectural clarity, and measurable impact.

All projects →
2026·Developer Tooling / Product Engineering
In Progress

Callman

Callman is a desktop-first developer and QA automation platform that combines API testing, collection management, dynamic environments, database/Kafka/Redis validation, node-based scenario building, contract testing, CLI execution, and enterprise-grade workflow automation into a unified system. Designed as a Postman-class platform with deeper operational testing, Callman enables teams to build, validate, automate, and operationalize complex system behaviors across APIs, databases, event streams, and infrastructure layers.

6+ tool categories → 1 platformUnified tooling reduction
Major reduction in manual cross-system validationQA workflow acceleration
Request → DB → Kafka → Redis → Script → ConditionAutomation depth
ElectronReactTypeScriptNode.jsExpress.js+7
2024 - Present·Engineering Intelligence Platform
In Progress

GitSense

GitSense is a full-scale enterprise engineering intelligence platform built to transform raw GitLab activity into actionable business, delivery, workforce, and executive insights. Designed for large organizations with complex tribal/squad structures, GitSense ingests GitLab users, projects, commits, merge requests, reviews, discussions, approvals, pipelines, and DORA metrics into a unified analytics engine. Beyond traditional Git analytics, it introduces Workforce Intelligence, Product Delivery Economics, Portfolio Intelligence, Org Suggestion Systems, and advanced engineering graph capabilities — enabling leadership to measure not just code activity, but business efficiency, salary utilization, product health, and strategic execution quality.

10+Analytics dimensions
100+Engineering metrics
Incremental + Recovery-safeSync architecture
Node.jsTypeScriptExpress.jsMongoDBRedis+9
2023·Media Platform
In Production

edu-live.com

edu-live.com is a globally accessible education-focused digital platform designed to aggregate and distribute international educational news, scholarship opportunities, academic programs, institutional announcements, and career-growth pathways for students across 50+ countries. Built end-to-end with Node.js, Express.js, and MongoDB, the platform includes a fully custom backend ecosystem and administrative control panel engineered for scalable publishing, multilingual-friendly growth, category-rich content operations, and international audience reach. More than a conventional content site, edu-live functions as a global education opportunity infrastructure connecting users with actionable academic and professional pathways.

50+ countriesAudience reach
Global education opportunity ecosystemPlatform scope
Full backend + admin platformSystem ownership
Node.jsExpress.jsMongoDBJavaScriptREST API+6
03./Axioms

Operating principles

The beliefs that shape how I approach system design, code, and engineering decisions.

P₁01

Correctness before scale

Scale amplifies both strengths and flaws. A system that scales incorrectness is more dangerous than one that fails early. Reliability, transactional integrity, and correctness are foundational — performance comes after truth.

P₂02

Explicit contracts over hidden assumptions

Every boundary — API, event, database, or team — should define guarantees, failure modes, and expectations clearly. Undefined assumptions become operational debt under load.

P₃03

Composable systems over fragile complexity

Systems should evolve through composition, not entanglement. Modular services, typed boundaries, and clear responsibilities create architectures that survive growth.

P₄04

Observability is part of the design

A deployment without instrumentation is an untested theory. Logging, metrics, tracing, and measurable feedback loops are not optional afterthoughts — they are architecture.

P₅05

Maintainability compounds like technical capital

Shortcuts often borrow against the future with interest. Clean abstractions, operational clarity, and long-term maintainability are force multipliers for both product and engineering velocity.

04./Constructs

Products & tools built

Systems I have designed, built, or led — from consumer-facing platforms to internal engineering tooling.

Engineering Analytics

GitSense

Founder, Architect & Product EngineerOn-premise

GitLab engineering intelligence platform that ingests repositories, merge requests, pipelines, approvals, and team activity into actionable analytics for productivity, DORA metrics, code health, and organizational performance.

On-premise deployment — contact for access

Node.jsTypeScriptMongoDBReactGitLab APIAnalyticsETL
Developer Productivity

Callman

Founder, Product Architect & EngineerDesktop app

Postman-inspired desktop API platform focused on advanced request management, environment systems, contract validation, developer workflows, and premium product-grade API tooling.

Desktop application — early access available

ElectronReactTypeScriptNode.jsMongoDBAPI Tooling
Developer Tooling

Azericard Payment Integration

Creator & MaintainerOpen source

Open-source Node.js payment integration library for Azericard gateway systems, designed to simplify secure payment processing, transactional communication, and banking gateway integration for developers building fintech products.

Node.jsTypeScriptPayment SystemsAzericardNPMFintech
05./Variables

Knowledge map

The technical domains I work within, from daily production tools to deeper areas of specialization.

Full map →
expert

Backend Architecture

Architecting production-grade backend ecosystems: service boundaries, API contracts, protocol strategy, domain modeling, and system topology that scales cleanly from monolith to distributed platforms.

REST API Design
5y
WebSocket Systems
3y
Microservices Architecture
4y
Service Decomposition
4y
BFF Pattern
2y
API Gateway Design
2y
System Design
5y
expert

Distributed Systems

Designing resilient distributed platforms with practical consistency tradeoffs, event choreography, failure recovery, and concurrency-aware state management under production load.

Event-Driven Architecture
4y
Kafka
3y
Redis Pub/Sub
4y
Event Sourcing
2y
Eventual Consistency
3y
Distributed State Management
3y
Idempotent Processing
4y
Failure Recovery Patterns
3y
Concurrency Control
4y
λ
expert

Fintech Engineering

Engineering correctness-critical financial systems across payments, investment flows, transaction lifecycles, reconciliation, settlement, and margin-sensitive architectures.

Payment Systems
3y
Investment Systems
3y
J
expert

Java / Spring Ecosystem

Enterprise-grade JVM engineering across Spring Boot microservices, reactive architectures, secure backend infrastructure, and high-throughput backend systems.

Java 17–21
4y
Spring Boot
4y
Spring WebFlux
2y
Spring Data JPA
3y
Spring Security
3y
Hibernate
3y
Maven / Gradle
4y
Reactive Systems
2y
JVM Internals
3y
λ
expert

Node.js / TypeScript

Full-scale backend and product engineering with Node.js ecosystems spanning NestJS, Express, SSR infrastructure, enterprise APIs, and developer tooling products.

Node.js
5y
TypeScript
5y
NestJS
4y
Express.js
5y
Next.js SSR
3y
Type-safe API Design
4y
Authentication Systems
4y
High-concurrency APIs
4y
expert

Streaming / Messaging Infrastructure

Operational messaging systems for real-time event pipelines, asynchronous processing, stream consumers, and scalable cache-backed architectures.

Apache Kafka
3y
Kafka Consumer Groups
3y
Redis
4y
Redis Streams
2y
Pub/Sub Patterns
4y
Async Job Design
4y
Real-time Data Pipelines
3y
07. / Contact

Let's build something precise.

If you're working on a system that needs to be correct, fast, and maintainable at scale — I'm open to conversations about technical collaboration, consulting, or full-time roles.