に応じて・に応えて: the difference
に応じてN2
Meaning
Depending or based on, According to, In response to, Suitable for or to
Past papers
Tested once in past papers
Example
ジムでは実力に応じて、練習を選べるようにするべきだ。
Gyms should let you choose exercises that suit your ability.
に応えてN2
Meaning
In response to, Meet
Past papers
Tested once in past papers
Example
応援の声に応えて、勝利したチームが礼をした。
In response to the cheering, the victorious team bowed.
How to tell them apart
「に応じて」: adjusting to match the degree or change of A, or complying with a request.
「に応えて」: meeting other people's hopes or cheers (期待・声援・アンコール). 要望/依頼 can take both: に応えて (meet the wish) and に応じて (comply with the request). 「期待に応える」 (live up to expectations).
「次第で」: the result depends entirely on the first part. 「結果は君の努力次第だ」 (The result depends on your effort).