# Senior Backend Developer (Java) - Mobile Game Platform

**Company:** [UserWise Services](http://jobs.workable.com/companies/xnudHQAhPLna8DYoiomsgP.md)
**Location:** Lahore, Pakistan
**Workplace:** on site
**Employment type:** Full-time
**Department:** Engineering

[Apply for this job](http://jobs.workable.com/view/c017a75b-67d7-4866-851a-3741b1aff7e1)

## Description

**About the Role**

We are hiring a Senior Backend Developer to maintain and extend the backend for a live mobile game (Cocos C++ client + Java services). You will work on gameplay APIs, player data integrity, ranking systems, payments, and platform services in a high-traffic production environment.

**What Success Looks Like**  
\- You can safely ship new game operations without breaking existing client contracts.  
\- You improve reliability of account data and ranking flows under real player load.  
\- You reduce incident risk in transfer/payment paths through stronger validation and observability.  
  
**How to Apply**  
Please share:  
\- Resume and LinkedIn/GitHub profile  
\- Relevant backend project examples (especially game or high-scale transactional systems)  
\- Brief note describing your experience with Spring MVC + MyBatis + Redis

## Requirements

**What You’ll Work On**

Build and maintain Java backend services that power core gameplay and account flows.

Implement and evolve request handlers behind the game protocol endpoint (\`/bnb/operation\`) using \`requestKey\` dispatching.

Own data consistency across MySQL + Redis, including transactional and partial-failure edge cases.

Extend ranking, activity, and account transfer systems used by live players.

Integrate and support payment verification flows (Google Play / iOS / PayPal).

Collaborate with client engineers by tracing C++ network behavior and shared JSON contracts.

**Required Technical Skills**

**1) Java & Frameworks**

Strong Java 11 experience in production systems.

Spring MVC (XML-based configuration), Spring Security, Spring JDBC/Tx.

MyBatis (annotation-driven DAO patterns), not JPA/Hibernate.

Maven multi-module project experience.

**2) Networking & API Contract**

Deep understanding of HTTP/HTTPS API design and production debugging.

Experience with JSON-based messaging (Fastjson/Jackson/Gson interoperability).

Ability to work with command-style API routing (single endpoint + operation key) rather than conventional REST resource routing.

Familiarity with gzip-compressed request/response handling.

**3) Database & Caching**

MySQL schema design and performance tuning.

Redis (Jedis), including sorted sets, TTL patterns, and cache invalidation.

Confidence handling consistency between relational DB writes and Redis updates.

**4) Game Backend Domain Skills**

Leaderboards, player progression data, event systems, and anti-cheat validation logic.

Handling high-frequency state updates and large player-state payloads safely.

Idempotency, concurrency control, and rollback strategy for critical flows.

**5) Legacy / Cross-Stack Collaboration**

Ability to read C++ code to understand client request construction and field contracts.

Comfortable debugging cross-language issues between Cocos C++ client and Java backend.

**Nice to Have**

Experience with legacy Spring MVC modernization.

Prior migration of old connection pools (e.g., BoneCP) to HikariCP.

Experience with Google App Engine or similar cloud runtimes.

Experience with distributed locking (Redis / ZooKeeper/Curator).

## Benefits

-   Market competitive, tax-free USD salaries
-   Paid Time Off
-   Medical Health Insurance
-   Performance Bonus
-   Annual Performance Reviews