Skip to main content
Resume
H

Resume

Haylemichael Tsega

Senior Backend Engineer · Distributed Systems · FinTech · Cloud

remantsega@gmail.com+251 947 731 212github.com/Reman-tsegalinkedin.com/in/haylemichael-tsegaAddis Ababa, Ethiopia · UTC+3 · Remote

Professional Summary

Senior Full-Stack Engineer with 5+ years of production experience architecting high-throughput distributed systems, real-time financial platforms, and cloud-native microservices. Specialized in Node.js, TypeScript, and AWS serverless infrastructure, with a proven track record delivering mission-critical fintech systems — including automated reconciliation engines, payment gateways, and banking platforms serving 1M+ customers — in regulated, high-compliance environments. Deep expertise in event-driven architecture, Redis-backed performance optimization, multi-tenant SaaS design, and secure API development aligned with financial data security standards.

5+

Years Experience

1M+

Users Served

78%

Settlement Time Saved

3.81

University GPA

Work Experience

Senior Full-Stack Engineer

Current

EagleLion System Technology

Addis Ababa, Ethiopia

Feb 2025 – Present
  • ▸Architected a production-grade serverless backend on AWS Lambda and API Gateway for a banking Super App with 1M+ active users, sustaining sub-150ms P99 response times at 58,000+ concurrent requests per second.
  • ▸Engineered real-time event processing pipelines in Node.js and TypeScript to ingest and route high-frequency financial webhooks, reducing end-to-end event propagation latency by 60% through batching and async queue optimizations.
  • ▸Optimized AWS Lambda cold-start behavior through dependency pruning and provisioned concurrency, eliminating 2.8s of initialization overhead from payment flows and reducing cold-start frequency by 74%.
  • ▸Engineered 65+ RESTful API endpoints for 150,000+ active internet banking customers, maintaining strict PCI-DSS-aligned data security and input validation standards.
  • ▸Designed and deployed an Automated Reconciliation System synchronizing real-time balances across 280+ post office agency nodes, eliminating manual errors and reducing settlement cycle time by 78%.
  • ▸Integrated Redis distributed caching across high-frequency query paths, reducing primary PostgreSQL load by 72% and improving average API response time from 680ms to 140ms during peak hours.
Node.jsTypeScriptAWS LambdaAPI GatewayRedisPostgreSQLExpress.jsReact

Full-Stack Engineer

Independent (Freelance)

Addis Ababa, Ethiopia

Jan 2024 – Present
  • ▸Designed an event-driven geolocation ingestion engine processing high-frequency GPS streams and dynamic geofencing across 400+ active vehicles, tracking 5,000+ daily trips with zero-downtime real-time operations.
  • ▸Built a React/TypeScript admin dashboard with live map rendering and WebSocket real-time sync, enabling fleet operators to monitor vehicle status at 2-second refresh intervals with sub-500ms update latency.
  • ▸Architected a secure multi-tenant backend using Node.js, Express, and PostgreSQL with row-level tenant isolation and RBAC policies, supporting 18+ enterprise clients with zero cross-tenant data leakage incidents.
  • ▸Secured all tenant API endpoints with JWT authentication, rate limiting, and input sanitization — achieving clean results across 100% of penetration test checkpoints.
Node.jsTypeScriptReactNext.jsPostgreSQLWebSocketJWT

Full-Stack Engineer

Addispay Financial Technology

Addis Ababa, Ethiopia

Jan 2024 – Feb 2025
  • ▸Built full-stack transaction monitoring dashboards using React and TypeScript, enabling operations teams to track 35,000+ daily transactions with real-time status visibility, reducing average transaction review time by 40%.
  • ▸Secured payment gateway endpoints with JWT tokenization, HMAC request signing, rate limiting, and input sanitization — eliminating SQL injection and replay-attack vulnerabilities from all production endpoints.
  • ▸Reduced frontend dashboard bundle size by 38% through code-splitting and lazy loading, improving Time-to-Interactive by 2.1 seconds and cutting page load time from 4.8s to 2.7s.
ReactTypeScriptNode.jsExpress.jsPostgreSQLRedisJWT

Code Coach & Technical Instructor

Volunteer

Code Jika NGO

Addis Ababa, Ethiopia

2022 – 2023
  • ▸Mentored 90+ aspiring developers through structured web development curricula covering HTML, CSS, JavaScript, and full-stack project architecture, achieving an 85% course completion rate.
  • ▸Designed hands-on workshops introducing industry-standard Git workflows, code review practices, and agile habits to accelerate graduates' time to first job placement.
HTML5CSS3JavaScriptGit

Technical Skills

Languages

TypeScriptJavaScript (ES2022+)SQLGoBash

Frontend

React.jsNext.jsRemixTailwind CSSWebSocket Client

Backend

Node.jsExpress.jsRESTful APIsWebSocket ServersGraphQLMicroservices

Cloud & Serverless

AWS LambdaAmazon API GatewayAmazon S3Amazon EC2Amazon RDSServerless Framework

Databases & Caching

PostgreSQLMySQLMongoDBRedis

DevOps & Tooling

DockerGit / GitHubCI/CD PipelinesLinux

Architecture

Distributed SystemsMulti-Tenant SaaSEvent-DrivenServerlessMicroservices

FinTech Domain

Payment GatewaysAutomated ReconciliationAgency BankingInternet BankingPCI-DSS

Education

B.Sc. in Electrical and Computer Engineering (Computer Focus)

Addis Ababa Science and Technology University (AASTU)

Addis Ababa, Ethiopia · Class of 2023

★GPA 3.81 / 4.0 · Great Distinction

Distributed Networks · OOP Analysis · Advanced Data Structures · Software Systems Design

Associate of Science in Business Administration

University of the People

Online · US-Accredited · 2019 – 2021

Highlights

  • 🏦1M+ active users on EagleLion's banking Super App (AWS Lambda, sub-150ms P99)
  • ⚡78% reduction in settlement cycle time via Automated Reconciliation across 280+ agency nodes
  • 🏆Inobizz & Korean Embassy Prize — Property Security and Warehouse Management graduation project
  • 🎓Great Distinction — AASTU B.Sc. in Electrical and Computer Engineering (Computer Focus), GPA 3.81 / 4.0