Tab Completion

In the early days of AI coding, this was it and it is where the agentic engineering journey started for many. Tends to be not used much as there are newer patterns that give a better combination of efficiency with control and safety.

The flow

Software Engineer

Agent

In the context of hand coding inside existing software, The software engineer starts writing a line of code, function, or class body.

The software engineer presses Tab.

The agent gathers context from around the cursor, including comments and code errors.

The agent generates and presents a proposed completion.

The software engineer reviews the proposed completion:

5a.

Accepts the completion — The software engineer confirms the change.

5a.

The agent applies the completion.

5b.

Rejects the completion — The software engineer declines the change.

5b.

The agent makes no changes.

The interaction ends.

The ratings, in words

Speed

Low

Mostly just not getting stuck. Marginally faster than looking up the answer on stack overflow and copy/pasting.

Control

High

The Software engineer is in control of the process, can reject any increment, can provide as much context as they think is needed.

Quality

High

The incremental and 'small blast radius' of this approach results in quality equivalent to hand coding.

Safety

High

Again, Incremental and 'small blast radius' of this approach results in safety eqivalent to your own skill level. Care should obviously still be taken if you are completing a function in an Auth chain or similar high risk area.

Brainrot

Low

The lassitude of handing off the hard problem is countered by the immediate discovery of the answer and reinforced by seeing the code run succesfully.

Token use

Low

You are paying for a few hundred tokens of surrounding context per keystroke and nothing else. The cheapest pattern there is.

Best for

Established engineers who want to maintain control but increase efficiency marginally.

Tools

Microsoft Copilot