01
High-Concurrency Architecture
Design horizontally scalable microservices handling tens of thousands of CCU and tens of millions of daily events, balancing performance and maintainability.
Senior Backend Engineer / Tech Consultant
Wencong Cheng 鄭文聰
High-concurrency backends that stay stable, fast and maintainable
Go · C# | Kafka · K8s · GCP | Event-Driven × Data Consistency
Services
How I Can Help
From architecture design to production tuning — owning the technical decisions on critical backend modules.
02
Cloud-Native Deployment
Containerized deployment on GCP / GKE / Cloud Run, with CI/CD, observability and cost-performance tuning.
03
Event-Driven & Data Consistency
Kafka, Outbox/Inbox, idempotency and distributed locks to keep cross-service transactions exactly-once under heavy load.
04
Integration & Refactoring
Unify outbound APIs, decouple systems, and refactor legacy code for maintainability and stability.
Selected Work
Proven Results
Framed as Problem → Approach → Quantified Impact. Employers anonymized; described by domain.
A large-scale gaming platform — a full-stack iGaming live-betting platform built from zero in 91 days
Technical co-founder · architecture lead 13 repos · 1,591 commits ~5-person team × 6 months of output
Problem
A gaming platform still at the concept stage had to become a fully operational commercial system — from architecture and microservice decomposition to CI/CD, observability and team enablement.
Approach
As technical co-founder, led the platform architecture and tech choices: 13 microservices, the full live-betting flow (bet / settle / payout / bankruptcy top-up), WebSocket protocol, a pool engine with dynamic RTP control, event-driven + Outbox for zero dropped transactions, gRPC client-side LB, K8s GitOps and full-stack observability; built a reusable service scaffold and used AI-assisted delivery (Claude Code SDD) to accelerate — while taking the team from "new to microservices" to operating independently.
Impact
91 days concept to launch
13 microservice repos
1,591 Git commits
420K+ net lines of code
Asia iGaming B2B High-Concurrency Campaign Platform
CCU ~5,000 · peak 10,000+ DAU 90k–150k Largest MongoDB collection 3M+
Problem
A multi-integrator campaign platform needed to sustain tens of thousands of concurrent users and millions of daily events while guaranteeing zero error in Jackpot and budget-pool money logic.
Approach
Event-driven microservices on Kafka; Redis distributed locks for Jackpot Pool and Budget Pool (Lua / atomic ops); a unified outbound API proxy to reduce coupling; refactored sync scheduling and token-expiry cleanup.
Impact
×40 Jackpot sync scheduling perf
×10 Token-expiry cleanup perf
7–12M Kafka events per day
10,000+ Peak concurrent users
Manufacturing Core Systems Integration & Refactor
Problem
SCADA / MES / ERP(Baan) and Fanuc equipment were fragmented and tightly coupled; failed transactions were hard to recover and the legacy code was hard to maintain.
Approach
Integrated SCADA / MES / ERP with Fanuc equipment; introduced transaction idempotency and error-recovery; refactored the legacy architecture for maintainability and stability.
Impact
Idempotent Transactions & error recovery
4 systems SCADA/MES/ERP/Fanuc integrated
Self-built AI customer-service & knowledge platform
Public support + internal KB · end-to-end self-built Human-grade AI conversation · prompt-engineered & tuned Data on-prem · high availability · cost-controlled
Problem
A platform was needed for both public-facing anonymous AI support and internal knowledge-base Q&A: safe to expose to the internet, no internal-data leakage, cost-controlled, and answered by a real AI agent rather than canned scripts.
Approach
Professional-grade, 24/7 conversation with minimal staffing: a login-free, always-on smart agent for the public that greets, answers and guides enquiries, plus an internal AI teammate that turns scattered documents into instant answers and proactively helps troubleshoot and pinpoint issues — not just answering passively. Replies are genuinely reasoned by AI (not canned scripts) and continuously refined through prompt engineering and agent tuning for quality, accuracy and consistency — while keeping public availability high and internal data private at a controlled cost.
Impact
24/7 Always-on auto support
No login Zero friction for visitors
Instant Internal Q&A + proactive triage
On-prem Data private · cost-controlled
Tech Stack
Tools & Technologies
$ cat lang // Languages
- Go
- C# / .NET
$ cat arch // Architecture
- Microservices
- Event-Driven
- DDD
- Outbox / Inbox
- Idempotency
$ cat data // Messaging & Data
- Kafka
- MongoDB
- Redis
$ cat cloud // Cloud & Deploy
- GCP / GKE
- Cloud Run
- Kubernetes
- Docker
- CI/CD
- ELK
About
About Wencong
8+ years of backend development across two very different worlds — manufacturing and iGaming — from factory equipment integration to online platforms serving tens of thousands of concurrent users.
I independently own architecture design and technical decisions on critical modules, specializing in cloud-native deployment, high-concurrency systems and distributed data consistency. I like turning messy business logic into clear, testable, long-lived systems.
Contact
Let's talk about your project
Freelance, consulting or long-term — drop your needs and I usually reply within 24 hours.