Technical Project Manager

Technical Project Manager (Sage X3) – Hybrid Contract (Inside IR35)

Role Purpose

The Technical Project Manager will take full end-to-end ownership of the implementation of Sage X3, replacing the existing Agresso (Unit4) finance system. The role is delivery-focused and hands‑on, accountable for planning, execution, stakeholder engagement, and successful go‑live, ensuring the new system meets business, financial, and compliance requirements. This individual will act as the single point of accountability, bridging finance, IT, implementation partners, and senior stakeholders.

Ideal Candidate Overview

This role suits a pragmatic, delivery‑driven ERP / Finance Project Manager with deep experience implementing finance systems in complex organisations. They will be comfortable operating at both strategic and operational levels, able to roll up their sleeves while maintaining control of governance, risk, and delivery milestones. They will have a strong understanding of finance processes, proven experience of ERP migrations, and the confidence to challenge stakeholders where required.

Core Responsibilities

Programme & Delivery Ownership

• Take full ownership of the Sage X3 implementation lifecycle: discovery, design, build, test, data migration, cutover, and post‑go‑live stabilisation


• Develop and manage a detailed project plan, budget, resourcing model, and delivery roadmap


• Own project governance, RAID logs, and reporting to senior stakeholders

Stakeholder & Partner Management

• Act as the primary interface between finance leadership and end users, IT and data teams, Sage X3 implementation partners and vendors


• Manage third‑party partners, holding them accountable for scope, quality, and timelines


• Facilitate workshops and design sessions to translate business requirements into system solutions

Finance & Systems Expertise

• Lead the migration from Agresso (Unit4) to Sage X3, including chart of accounts redesign, data migration and reconciliation, reporting and consolidation impacts


• Ensure system design supports financial controls, audit requirements, regulatory and statutory reporting

Hands‑On Execution

• Be actively involved in requirements definition, UAT planning and execution, cutover planning and go‑live readiness


• Proactively identify and resolve issues rather than escalating prematurely

Change & Adoption

• Support business change, user readiness, and training strategies


• Ensure finance teams are confident and operationally effective post‑implementation

Required Experience & Background

Essential

• Proven track record delivering ERP finance system implementations as Project Manager


• Direct experience implementing Sage X3


• Experience replacing or migrating from Agresso / Unit4 or similar legacy finance platforms


• Strong understanding of: general ledger, AP / AR, fixed assets, budgeting, reporting, and financial controls


• Experience managing external system integrators and vendors

Desirable

• Background in finance transformation or systems roles


• Experience working in multi‑entity or multi‑currency environments


• Formal project management qualification (PRINCE2, PMP, Agile, or equivalent)

Key Skills & Competencies

• Delivery‑focused: prioritises outcomes over theory


• Hands‑on: comfortable operating in the detail, not just steering from above


• Commercially astute: understands cost, value, and business impact


• Structured & organised: strong planning, documentation, and reporting discipline


• Resilient & assertive: able to challenge senior stakeholders and suppliers


• Clear communicator: translates technical detail into business‑friendly language

Personality & Working Style

• Accountable and ownership‑driven


• Calm under pressure, particularly around go‑live


• Pragmatic problem‑solver


• Credible with finance leaders and technical teams alike

Success Measures

• Sage X3 delivered on time, on budget, and fit for purpose


• Clean data migration and successful cutover


• Minimal post‑go‑live disruption


• High user adoption and confidence within finance teams

Candidate Requirements

All our roles are UK based. When submitting your application to Colossus, please ensure the following:

• Your CV has your address and postcode.


• You also have your correct phone number and email address so we can contact you ASAP regarding your application.


• For confidentiality purposes, please remove any reference contact phone numbers and email address details from your CV.