Informix 4GL Developer - Enterprise ERP & Supply Chain Systems

We are hiring an Informix 4GL Developer on behalf of a UK enterprise operating in the manufacturing and distribution sector. This business runs a high-throughput operation across production sites, with systems that underpin everything from materials planning and warehouse execution through to financial posting and customer fulfilment.

You'll be joining a team responsible for mission-critical applications that cannot stop-supporting, enhancing, and modernising a mature platform while keeping reliability, performance, and auditability front and centre.

This is ideal for someone who enjoys hands-on development, problem-solving in live operational environments, and improving legacy systems without "big bang" risk.

What you'll be doing

You'll work closely with technical peers and business stakeholders across manufacturing, warehousing and finance, delivering changes safely and keeping services stable., * Design, build and enhance applications using Informix 4GL (including maintainable program structure, reusable modules, and robust error handling).

• Collaborate with senior engineers and business SMEs to translate operational needs into scalable, supportable solutions.
• Troubleshoot and resolve production issues across application and database layers-driving root-cause fixes rather than repeated workarounds.
• Support structured testing cycles: integration testing, UAT, regression testing, and performance testing with clear evidence and traceability.
• Improve system performance and reliability through SQL optimisation, indexing strategy, query tuning, and careful control of transactional behaviour and locking.
• Participate in change delivery and IT projects: impact analysis, estimation, release planning, and controlled deployment.
• Maintain technical documentation: runbooks, support notes, data flows, interface specs, and change logs for audit/compliance.
• Resolve incidents and requests in line with agreed SLAs, including participation in a paid out-of-hours rota when required.

Tech stack (what you'll be working with)

This is a genuinely "core systems" role, deep engineering, data integrity, and operational resilience., * Database performance tooling/skills: understanding of query plans, indexing approaches, statistics updates, and diagnosis of locking/contention

• Informix ecosystem knowledge: Informix SPL (stored procedures), CSDK/ESQL exposure, ODBC/JDBC connectivity
• Integration experience: EDI, XML, REST APIs, flat-file interfaces, secure file transfer, scheduling (e.g. cron)
• Secondary database knowledge: Microsoft SQL Server or Oracle SQL
• Source control and delivery practices: Git, release branching, change control, automated checks, peer review
• Familiarity with structured support processes (e.g. ITIL incident/problem management)

Domain exposure (what the systems support)

You'll be building and supporting applications tied directly to operational outcomes, including:

• ERP / Supply Chain processes (order lifecycle, stock movements, replenishment)
• Warehouse Management (receipts, put-away, picking, packing, dispatch confirmation)
• Manufacturing operations (work orders, production reporting, BOM consumption)
• Finance workflows (invoicing, postings, reconciliation outputs, audit trails)
• Shipping artefacts such as labels, manifests and carrier-facing data feeds

What success looks like in the first 3-6 months

• You'll take ownership of key application areas and become trusted for Informix decision-making.
• You'll stabilise and improve at least one high-impact workflow (performance and/or defect reduction).
• You'll help tighten delivery: better regression coverage, clearer documentation, safer releases.
• You'll contribute to a pragmatic modernisation path-improving integrations and maintainability without disrupting operations.

• Informix 4GL development (structured coding, modularisation, validation, exception handling patterns)
• Strong SQL (joins, aggregation, subqueries, performance thinking, transaction control)
• Informix Dynamic Server (IDS) fundamentals (sessions, locks, storage, backup awareness, basic monitoring)
• Unix/Linux administration basics (processes, file permissions, log inspection, shell scripting)
• Exposure to enterprise Unix variants such as HP-UX (or willingness to work in HP-UX estates), * Commercial experience delivering and supporting systems using Informix 4GL
• Strong problem-solving approach across both application code and IDS/SQL layers
• Comfortable working with business stakeholders in operational environments where uptime matters
• A mindset for quality: clean code, documentation, testing discipline, and continuous improvement