Implementation engineer: taking software live at a customer site

An implementation, from signed contract to handover

A typical mid-sized project runs through recognisable phases, even when the names differ:

The engineer usually works alongside a project manager who owns the timeline and a functional consultant who owns the process design. On smaller teams, one person does all three.

The artefact: a go-live cutover checklist

Go-live is where implementation reputations are made or lost. This checklist is for a hypothetical payroll system replacement at a company with 2,000 employees, cutting over on a weekend so that the first live payroll runs at month-end.

CUTOVER PLAN — Payroll go-live, Saturday–Monday

T-7 days
[ ] Go/no-go criteria agreed in writing with customer HR and finance heads
[ ] Final UAT sign-off received; open defects all rated minor, with workarounds noted
[ ] Rollback plan written: old system stays read-write until Monday 10:00

T-1 day (Friday)
[ ] Old system frozen for new joiners/leavers at 18:00; late changes go on a paper log
[ ] Access list for Monday confirmed: 14 HR users, 3 finance users, SSO tested for each

Saturday
[ ] 09:00 Extract employee master, salary structures, YTD earnings and tax declarations
[ ] 11:00 Load into production
[ ] 13:00 Reconcile: headcount 2,000 = 2,000; total YTD gross matches old system to the rupee
[ ] 15:00 Parallel run: last month's payroll recomputed in the new system; differences explained
[ ] 18:00 Go/no-go call: all checks green, or roll back and reschedule

Sunday
[ ] Bank file format tested with a zero-value test file accepted by the bank's portal
[ ] Paper log of Friday–Saturday changes entered and double-checked

Monday
[ ] 09:00 Users log in; hypercare channel staffed until 20:00
[ ] 10:00 Old system set to read-only if no blocking issue
[ ] 17:00 Day-one issue list sent to customer with owner and ETA for each

Three features make the checklist work. The go/no-go criteria are agreed a week before, not debated at 18:00 on Saturday. The reconciliation compares to the rupee and to the head, because payroll errors reach people's bank accounts. And the rollback plan is real: the old system stays usable until the new one proves itself.

A normal week mid-project

• Monday: configuration workshop on leave policies with the customer's HR team.
• Tuesday: write and test the migration script for three years of attendance history.
• Wednesday: debug an integration where the customer's ERP rejects files with a trailing newline.
• Thursday: weekly status call; two items slipped because the customer's IT has not opened a firewall port.
• Friday: document the configuration decisions made this week so support can understand them later.

On-time go-lives and post-launch data errors

• On-time go-live against the agreed plan, with scope changes documented.
• Defects found after go-live, especially data errors.
• Customer satisfaction at go-live and at handover.
• Hours spent against the estimate, since many implementations are fixed-fee.
• Quality of the handover, measured by how often support has to come back asking.

Project managers, functional consultants and client IT

Usually an implementation or professional services manager. You work with project managers, functional consultants, the product and engineering teams (for bugs and product gaps), sales and customer success, and on the customer side their IT, process owners and end users.

Confused with forward deployed engineer and solutions engineer

A solutions engineer works before the sale, proving fit. An implementation engineer configures a mostly finished product after the sale. A forward deployed engineer is embedded with a customer to build new capability on top of a platform, often writing substantial code and feeding product changes back; the comparison is covered in solutions engineer vs forward deployed engineer and in the FDE hub.

Onboarding, hypercare and ETL in implementation postings

• "Client onboarding, go-live, hypercare" — project delivery with deadlines.
• "Data migration, ETL, SQL" — scripting and reconciliation work.
• "REST APIs, SFTP, webhooks" — integration work.
• "Functional knowledge of HR/payroll/finance" — domain matters as much as code.
• "Travel to client sites" — ask how often; some roles are heavily on-site.

Shadow a go-live, then run one

Month one: shadow a live implementation and read the last three handover documents. Month two: own migration or integration for one project. Month three: lead a small go-live end to end. Next roles include senior implementation engineer, implementation lead, solutions architect, or forward deployed engineer. The FDE for Freshers programme covers the SQL, APIs, cloud basics and client communication this path uses.