Freelance Java Backend Developer Jobs in New Jersey

Role Overview We are looking for a highly experienced, deeply hands-on Team Lead- Java Back-End Developer to drive day-to-day engineering execution on the Digital Assets Platform. The successful candidate will focus on core backend/platform software engineering leadership: and write production code regularly, leads by example, enforces engineering rigor, and is the technical backbone that junior and mid-level engineers rely on for direction, review, and mentorship. The ideal candidate will bring at least 6 to 10+ years of hands-on development experience and has "been in the trenches" - someone who can jump into a complex codebase, spot subtle bugs and design flaws during code review, drive low-level design (LLD) discussions with authority, and unblock the team on the hardest technical problems.

This person is expected to be more experienced and technically sharper than the other developers on the team, acting as the de facto technical authority and quality gatekeeper for the squad. Key Responsibilities Hands-On Technical Leadership Actively write, review, and ship production-quality code alongside the team - this is not a purely managerial or coordination role. Personally take ownership of the most complex, high-risk, or ambiguous engineering problems on the platform.

Set the technical direction for the team's day-to-day implementation work, ensuring consistency with overall platform architecture. Code Quality & Code Review Perform rigorous, detailed code reviews across the team's pull requests, catching subtle logic errors, concurrency issues, security gaps, performance bottlenecks, and maintainability problems before they reach production. Establish and enforce coding standards, review checklists, and best practices (clean code, SOLID principles, secure coding, testability).

Act as the final technical quality gate prior to merge/release for critical components. Low-Level Design (LLD) Drive low-level design sessions, translating high-level architecture and requirements into detailed, implementable technical designs (class/module structures, API contracts, data models, sequence flows, error handling strategy). Review and challenge design proposals from other engineers, ensuring designs are scalable, resilient, and aligned with platform standards.

Document key design decisions and trade-offs for traceability and knowledge sharing. Team Leadership & Mentorship Directly manage and/or technically lead a squad of backend/platform engineers, providing day-to-day technical guidance and unblocking impediments. Mentor junior and mid-level engineers, raising the overall technical bar of the team through pairing, reviews, and structured feedback.

Identify skill gaps and growth opportunities within the team; contribute to hiring and technical interviewing. Delivery Ownership Drive the team's sprint/iteration execution - decomposing epics into well-scoped technical tasks, estimating effort, and ensuring on-time, high-quality delivery. Proactively identify technical risks, bottlenecks, and debt; escalate and resolve issues before they impact delivery timelines.

Partner closely with the Engineering Team Lead (SVP), Architect, and Product/Business stakeholders to translate requirements into a sound technical execution plan. Engineering Excellence Champion automated testing (unit, integration), CI/CD discipline, observability, and operational readiness for everything the team ships. Identify and remediate technical debt, legacy pain points, and recurring production issues.

Stay current on backend engineering, distributed systems, and platform reliability best practices (deliberately not a smart contract/Web3-first role - the emphasis is core software engineering excellence). Qualifications 6 -10 years of hands-on professional software development experience, with demonstrated depth in backend engineering (e.g., Java, Spring Boot, distributed systems, microservices, REST/gRPC APIs). Proven track record of leading by doing - an engineer who still codes regularly and is respected for technical depth rather than title alone

Strong, demonstrable experience conducting thorough, high-signal code reviews and catching issues that others miss (correctness, security, performance, edge cases, race conditions). Strong command of low-level design - able to independently produce and critique detailed technical designs, not just high-level architecture diagrams. Experience leading or technically mentoring a team of engineers (formal management experience a plus, but technical leadership is essential).

Solid understanding of software engineering fundamentals: data structures & algorithms, design patterns, concurrency, database design, API design, and testing practices. Experience working in large-scale, regulated, or enterprise environments (financial services experience strongly preferred). Excellent communication skills - able to explain complex technical trade-offs clearly to both engineers and senior stakeholders.

Education Bachelor's degree in Computer Science, Engineering, or related field (or equivalent practical experience). Preferred Prior exposure to blockchain, distributed ledger, or digital asset platforms (as context, not as a primary skill requirement - this role is intentionally weighted toward core engineering depth over Web3/smart contract specialization). Experience with CI/CD pipelines, containerization (Docker/Kubernetes/OpenShift), and cloud-native architectures.

Experience operating in an Agile/Scrum delivery model. Prior formal people-management experience (performance reviews, career development conversations). ------------------------------------------------------ Job Family Group: Technology ------------------------------------------------------ Job Family: Applications Development ------------------------------------------------------ Time Type: Full time ------------------------------------------------------ Primary Location: New York New York United States ------------------------------------------------------ Primary Location Full Time Salary Range: $142,320.00 - $213,480.00 In addition to salary, Citi's offerings may also include, for eligible employees, discretionary and formulaic incentive and retention awards

Citi offers competitive employee benefits, including: medical, dental & vision coverage; 401(k); life, accident, and disability insurance; and wellness programs. Citi also offers paid time off packages, including planned time off (vacation), unplanned time off (sick leave), and paid holidays. For additional information regarding Citi employee benefits, please visit citibenefits.com

Available offerings may vary by jurisdiction, job level, and date of hire. ------------------------------------------------------ Most Relevant Skills Please see the requirements listed above. ------------------------------------------------------ Other Relevant Skills For complementary skills, please see above and/or contact the recruiter.

------------------------------------------------------ Anticipated Posting Close Date: Sep 11, 2026 ------------------------------------------------------ Automated Processing and AI We use automated processing, including artificial intelligence, for our legitimate business interests (or our reasonable and appropriate business purposes) to identify and align the candidate's skills and abilities with a specific job opening. Additionally, if you so choose, or consent, we can match your skills and abilities to other suitable roles at Citi. Importantly, all our hiring processes and decisions, including determining your suitability for a role, are conducted, checked, and decided by individuals.

Our automated processing and AI do not involve relying on automatic or autonomous decision-making. Please refer to any Jurisdictional Considerations, with specific provisions for your country (where relevant) for further details. Illinois residents - AI Notice and Right ------------------------------------------------------ Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law.

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